The invention relates generally to wireless network communications, and more particularly to wireless network systems and methods for efficiently delivering multimedia messages.
Mobile terminals (e.g., mobile phones, PDAs, etc.) have become a popular means to communicate with other people. Messages in various forms, e.g., voice, text, data, graphics, audio, video, etc., can be sent and received via mobile terminals. As mobile terminals become more and more popular, numerous functions are added and enhanced. One such function is to allow multimedia messages to be communicated between mobile terminals. Multimedia messaging depends on high speed of transmission. With introduction of advanced wireless communications technologies, such as GPRS (General Packet Radio Service) and high speed 3G (Third Generation Mobile System) technologies, sending and receiving multimedia messages have become practical. In sending and receiving multimedia messages, several industry standards have been proposed. One such standard is the Multimedia Messaging Service (MMS), which is defined by the 3GGP (Third Generation Partnership Project) Technical Specifications: 3GPP TS 22.140, 3GPP TS 23.140 and 3GPP TS 26.140. This standard allows users to use mobile terminals that support the MMS standard, and web sites if the web server supports the MMS standard, to send and receive MMS messages via a MMS user agent in formatted text, graphics, photographic images, audio and video clips. A MMS user agent refers to an application residing on a user equipment (UE), a mobile station (MS) or mobile terminal or an external device that performs MMS-specific operations on a user's behalf. Thus, a MMS user agent may be an application residing on a mobile phone or even a web server.
The MMS standard supports standard image formats such as GIF (Graphics Interchange Format) and JPEG (Joint Photographic Expert Group), video formats such as MPEG (Motion Pictures Experts Group) 4, and audio formats such as MP3 (MPEG-1 Audio Layer-3) and MIDI (Musical Instrument Digital Interface). Thus, video sequences, audio clips and high-quality images can be downloaded to the mobile terminals from WAP (Wireless Application Protocol) sites, transferred to the terminals via an attached accessory, such as a digital camera, or received as a MMS message. Photographs, audio and video clips may be stored in the mobile terminals for later use. MMS messages can also be sent either to another MMS-enabled mobile terminals or to an e-mail address.
FIG. 1 shows a MMS reference architecture 10 as defined by 3GPP (Third Generation Partnership Project), which is an organization that develops specifications for a 3G system. In FIG. 1, a MMS relay/server 20 is connected to various elements, including a billing system 32, MMS VAS (value added service) applications 34, MMS user databases 36, a HLR (home location register) 38, and a plurality of external servers 42 to 48 for providing functionalities such as E-mail, fax, SMS, etc. MMS relay/server 20 is also connected to a “foreign” MMS relay/server 40, which is located in a MMSE (Multimedia Messaging Service Environment) different from the MMSE in which MMS relay/server 20 is located. A MMSE refers to a collection of MMS specific network elements under the control of a single administration and may include more than one MMS relay/server. Connection between MMS relays/servers 20 and 40 allows communications between a MMS user agent A in one MMSE and a MMS user agent in another MMSE.
FIG. 2 is a simplified diagram illustrating how a multimedia message (MM) is delivered between two MMS user agents within the same MMSE in a conventional way. A MMS user agent provides the following application layer functionalities: initiating delivery of a MM to another MMS user agent, retrieval of a MM, terminal capability negotiation, and optionally MM composition, MM submission, and MM presentation, etc. A MMS relay/server, on the other hand, is responsible for providing storage, generating notifications and reports, and general handling of messages. A MMS relay/server also provides other functionalities such as generating charging data records (CDR) for billing purposes. In FIG. 2, a MMS user agent A can send a MM to another MMS user agent C and vice versa, via MMS relay/server 20. For example, a MMS user agent A can submit a MM to MMS relay/server 20 via WAP or TCP/IP. MM relay/server 20 will forward the MM to user agent C.
FIG. 3 is a simplified diagram illustrating how a MM is delivered between two MMS user agents located in two different MMSEs in a conventional way. As shown in FIG. 3, a MM user agent A can send a MM to MMS user agent B via MMS relay/server 20 via WAP or TCP/IP. MM relay/server 20 will forward the MM to user agent B via MM relay/server 40.
The conventional ways of delivering MMs between different user agents in the same or different MMSEs, as illustrated above, suffer from serious drawbacks. A main drawback is that it wastes valuable network resources, particularly with respect to MMS relay/servers since the MMS relay/servers are required to process and forward voluminous MMs exchanged among numerous MMS user agents. In other words, all the MMs sent to or pushed from a MMS user agent must go through at least one MMS relay/server. For example, the MMS relay/server will have to receive a MM from a MMS user agent and then forward the same message to another MMS user agent, even if the two MMS user agents are located in the same MMSE. Thus, at least two transactions are required, i.e., delivering a MM by a MMS user agent to a MMS relay/server and then forwarding the same MMS by a MMS relay/server to another MMS user agent. If the two MMS user agents are located in two different MMSEs, an additional transaction is required to transfer the MM from one MMS relay/server and another MMS relay/server. This will inevitably cause significant delays in delivering the MMs. Further, it requires high performance servers with a very large storage capacity since MMs are typically very large in size. This will add considerable costs for the MMS service provider to deploy and maintain the network.
Therefore, there is a need to provide a wireless network system for efficiently delivering MMs that not only saves the valuable network resources, but also speeds up delivery of the MMs between two MMS user agents.